US officials said today that highly pathogenic avian influenza (HPAI) has been detected on a commercial poultry farm in Tennessee after birds began dying last week. This is the first HPAI outbreak in the United States this year.

Seven hundred birds died from avian flu and another 72,800 were destroyed, according to a report from US Department of Agriculture (USDA) officials to the World Organization of Animal Health (OIE). The outbreak began on Mar 1, involves an H7 strain, and is listed as continuing.

The birds were part of a commercial chicken broiler-breeder flock, and according to the Tennessee Department of Agriculture (TDA), the farm is under quarantine, as are six other poultry farms within a 30-mile radius. The outbreak occurred in Lincoln County, in the south central part of the state.

"Animal health is our top priority," said state veterinarian, Charles Hatcher, DVM, in a press release from the TDA. "With this HPAI detection, we are moving quickly and aggressively to prevent the virus from spreading."

'Wait and see' mode

According to the USDA's Animal and Plant Health Inspection Service (APHIS) today, results of further virus testing, which will identify the exact strain of HPAI, will be available in the next 48 hours.

"Right now we’re in 'wait and see' mode," Andrew Bowman, DVM, PhD, told CIDRAP News. He is from the Animal Influenza Ecology and Epidemiology Program at The Ohio State University. "The regulatory agencies are responding swiftly, and it's justified."

No other flocks near the farm have shown signs of HPAI, which is not likely to cause human illness. HPAI can devastate flocks of poultry, however, prompting severe economic losses for the agricultural industry.

This year, Europe has had one of the most active avian flu seasons in history, with hundreds of poultry farms and wild birds dying from highly pathogenic strains that migrated with waterfowl from Siberia to the Middle East and Europe. So far this season, the United States has reported only isolated HPAI in wild birds in Montana and Alaska.

"It's always concerning when we have HPAI in commercial flocks," said Bowman. "But right now it's too early to know much."

This is the first time HPAI has been detected in Tennessee, according to the TDA, but low-pathogenic avian flu has been detected before.

"Although this is a situation no state wants to face, Tennessee has been actively preparing to respond to HPAI since it was first identified as a threat," said Commissioner of Agriculture Jai Templeton in the TDA release.

The USDA warned poultry farm owners and operators to practice good hygiene and report any illnesses in birds to state officials immediately.

Two years ago HPAI H5N2 caused almost 50 million poultry deaths in 15 US states and billions of dollars in economic damage.